Telephone-exchange system



A. RAYNSFORD.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED 050.31. I9I9.

1,386,730, PatentedAug. 9, 1921;

2 SHEETS-SHEET I.

I I I b IIII-{I- i: I'H" v //I ven for Arlhur Raynsford.

by M fly A. RAYNSFORD.

TELEPHONE EXCHANGE SYSTEM- APPLICATION FILED 050.31; 1919.

UNITED STATES PATENT OFFIQE.

ARTHUR RAYNSFORD, OF NET/V YORK, N. L, ASSTGNOR 'lO VJ'ESTERN ELECTRIC COM- PANY, INCORPORATED, OF HEX/V YORK,

I. 1., A COBPORATZON OF NE'VV YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed December 31, 1919.

New York, in the county of New York,

State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the t0llowing is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to such systems involving an automatic exchange and a toll exchange. More specifically the invention relates to means for indicating to an operator at a toll exchange the class of service to which a subscriber, whose line has been extended to her position is entitled. For example, some stations of an automatic exchange may be entitled to toll connections, while others may not.

The object of the invention is to provide in a system of this nature, means for automatically indicating to an operator whether a calling line, which has been extended to her position, is entitled to toll connections or not.

A feature of the invention consists in the provision of means for inductively transmitting a tone, over two conductors of a trunk circuit extending between two exchanges, to an operators telephone set con nected to the trunk, with means under the control of the operator for disconnecting the tone from her set and reconnecting it at will.

in the drawings, Figures 1 and 2 placed side by side represent the circuit arrangements of one embodiment of the invention, only so much being shown of the circuits and pparatus as is necessary for a clear understanding of the present invention. The circuits and apparatus shown in Fig. 1 are located at the automatic exchange while those shown in Fig. 2 are located at the toll or manual exchange.

A calling subscriber, of the automatic exchange whose station is indicated at A, extends his line to an operators position at the toll Or manual. exchange shown in Fig. 2 by operating switches under the control of sender The line finder B and selector switch C schematically represented may be of the type disclosed in the Patent No. 1,334,300., to Charles L Goodrum, issued Specification of Letters Patent.

Patented Au. 9, 1921.

Serial No. 348,511.

March 23, 1920, in which case induction coil 5, generator 41 and the connections therefor or the present drawing would take the place oi: the coil 135, generator 136 and the connections therefor shown in that patent. Lines not entitled to special service or to toll connections would be provided with a connection to the source of tone supply. That part of the apparatus of the trunk circuit extending between the automatic and toll exchange located at the automatic exchange is indicated in 1 as D while that part located at the manual or toll ex change is indicated in Fig. 2 as E. The trunk circuit terminates at the manual exchange in a jack 111. A cord circuit F located at the operators position isshown in Fig. 2, to which an operatorstelephone set is normally connected. The operation of the system is such that as soon as the operator plugs into the jack of a trunk over which a call has arrived, the tone is heard in the set of the operator if the line is not entitled to tell connections. Terminating at the operators position in jack 126 and extending to a chief operators or supervisors desk, is a trunk circuit G, by means of which the L tor may extend the line of a calling suliscriber to the chiefoperator in case any di ute arises as to the right of the calling st on to have a toll connection. A cord ci cuit H is provided at the desk by means of which the desk operator may converse with the calling subscriber.

lVith this description of the elements it is thought the invention will be more tully understood by reference to the following detailed description of the operation.

A subscriber at substation A desiring a.

toll connection removes the receiver from the switchhook and operates the sender S to select an idle trunk leading to the toll exchange in the manner described in the above mentioned patent.

hen the calling substation A is ex-' completes a circuit at its front contact and left-hand armature for slow-to-release relay 1.1. Relay 11 in attracting its armatures removes ground from terminal 31 of the trunk circuit thereby rendering the trunk busy and completes a circuit for slow-to-release relay 12. The latter circuit may be traced through ground, frontcontact and inner right-hand armature of relay 11, and winding of relay 12 to grounded battery. Relays 10 and 12 in operating complete a circuit through relay 13 in that portion of the trunk circuit D at the automatic exchange and for relay 101 in that portion of the trunk circuit at the toll exchange, This circuit maybe traced as follows: grounded battery, front contact and armatureof relay 12, right-hand winding of relay 13, upper left-hand winding of repeating coil 102, through the lefthand and right-hand windings of rcla; 101 in series, lower left-hand winding of repeating coil 102, right-hand armature a d front contact of relay 10 and left-hand wind-' ing; of relay 13 to ground. Relay 13 is mar ginal and will not operate in series with the right-hand winding of relay101 due to the high resistance of such winding. Relay 101 in operating completes a parallel circuit for ringing relay 104, and line signal 105 which may be traced from ground, armature and. front contactv of relay 101, lefthand normal contactsof relay 106, and thence through the winding of relay 104 and line signal 105' in parallel, to grounded batter Re lay 101 in energizing connects a sourc ringing tone to the trunlr which serve a signal to the calling subscriber that tie toll operator is being signaled and signal 105 in lightingindicates to the operator tlr t a call has arrived over the trunk with which it is associated.

The operator at the toll exchange observing the line signal inserts plug 110 intojaclr 111 whereupon a circuit is completed for relavs 113 and 112 in series, said circ tending om ground, winding of rela sleeves of jack 111 and plug 110, tl rough the winding of relay 112 to grounded battery. Relay 113, in operating, at its front contact and inner left-hand armature, shunts the right-hand, high resistance winding of relay 101 which permits the marginal relay associated with the trunk circuit at the automatic exchange to operate in series with the low resistance, left-hand winding of relay 101. Relay 113 in operating also completes a circuit for relay 106 which circuit extends from grounded battery. through winding of relay 106, right-hand armature and'front contact of relay 113 and righthand armature and back contact of relay 106 to ground. Relay 106 in operating locks p under control of relay 101, and opens the circuit for relay 104 and line signal 105. A circuit for relay 120 is prepared and it will operate in series with relay 106 as soon as the direct path to ground through the front contact and armature of relay 101 is opened.

Vhcn relay 13 at the automatic exchange is operated, a circuit is completed at its right-hand armature and front contact for relay 15. Relay 15 in operating completes a circuit at its outer armature and front ontact for relay 17 thereby inductively connectiug the source of tone supply to the operators telephone set, and at its inner armature and front contact, for relay 14;, which locks up under the control of relay 11. The circuit for the energization of relay 17 1 lay be traced as follows: ground, outer right hand armature and front contact of relay l5, outer left-hand armature and bark contact of relay 16, winding ofrelay 17, and left-hand armature and front contact of relay 10 to grounded battery. The path for the tone may be tracet as follows: grounded battery, secondary winding of induction coil 5, winding of cutoff relay 6, terminal 22, brush 25, brush 28, terminal 31, left-hand armature and front contact of relay 11, left-hand armature and front contact of relay 1'7, condenser 18, and primary winding of induction coil 19 to ground. The inter rupter 4, by means of the primary winding; of the coil 5 induces an alternating current in the secondary and over the circuit just traced. The primary winding of coil 19 induces a current in the secondary winding; of this coil which is in a circuit'which may he traced as follows: secondary winding' of coil 1.9,right-hand armature and front contact of relay 17, lower left-hand winding of repeating coil 102, condenser 160, upper left-hand winding of repeating coil 102. condenser 10 to the secondary winding of coil 151- From the left-hand winding); of repeatmgcoil 102, the alternating current is indu ed in the rightdiand winding and thence transmitted over a circuit to the operatofs telephone set (not shown). This circuit in eludes the secondary winding; of re 'ieating coil 102, upper and lower normal contacts of relay 120, tip and ring of aclr 111 and plug and the normally closed contacts of listening key 121.

The operator thus hears the tone as soon as plug 110 is inserted into the jack 111 and will inform the subscriber that toll connections from his station are not permitted.

After having heard the tone the operator may, in order to better converse with the calling" subscriber, actuate key 107 which results in the disconnection of the tone from the operators position. Actuation of key 10? establishes a circuitfor relay 103, which in operating opens theshunt around the opens the circuit for relay which deenergizes. Then relay 15 retracts its armatures, the circuit for relay 17 is opened. thereby opening the tone circuit leading to the operator, and a circuit for relay 16 is completed said circuit extending from ground, through the outer right-hand armature and back contact of relay 15 the winding of relay 16 and the right-hand armature and front contact of relay 1 1- to grounded battery. Relay .6 is then leld locked up under control of relays 11 and 36, the locking circuit extending from grounded battery, through the front contact and right-hand armature of relay 141, winding of relay 16, outer armature and back contact of relay 36, outer right-hand armature and front contact of relay 16 to the front contact andouter right-hand arniature of relay 11 to ground. Nhen key 1.0? is released relay103 decnergizes and in retracting its armatures again shunts the high resistance winding of relay 101, which P01311115 relay 13 and in turn relay 15 to operate over paths previously traced. Relay is then energized over a path extending from grounded battery, through the winding of relay 35. inner left-hand armature and front contact of relay 16, front contact and intermediate armature of relay 1.5 to ground. Relay then locks up'over a path including grounded battery, its winding trout contact and righthand armature. front contact and inner right-hand armature of: relay 16 to ground.

l1 he calling subscriber insists upon a connection the line will be extended over a trunk l to a supervisor or chief operator by inserting plug 125 into jack 126. Insertion of plug 125 in jack 126 completes circ-uit tor the energization of relay 128 said circuit extending through the sleeves o3? plug 125 and jack 1265 Relay 128 in opera. cornplctcs a circuit at itsarmature and front contact for relay 1.29. Belay 129 in operat ing e. :tends the calling line through to jack 131at the desk and bridges supervisory relay 130 across the calling end of the cord circuit. The operator then actuat-es ringing key 127whichcause's a signal 133 to be dis played at the desk. The chief operator or supervisor observing the signal inserts plug into ack thereby disvonnecting the signal 133 "from trunk G, and energizing supervisory relay 130 at the operators position over a circuit including battery and ground and the windings of relay 138, tip

' conductors of cordcircuit 15, trunk cuit (l cord circuit and the winding relay 130 which results in'the lighting of supervisory lamp 137.

The chief operator may'now converse with the calling subscriber and the operator and may request the operator to again place the tone on the circuit. The operator thereupon actuates key 107 which results in the ener gization of relay 103 and the deiinergization ot relays 13 and 15 as heretofore (lQSCl'lbGCl.

Relay 15 in retracting its armatures estabushcs a circuit tor relay 36, said circuit extending from grounded battery, through the wiudingot relay 36, left-hand armature and tront contact of relay 35, back contact and intermediate armature or relay 15 to ground. l elay 36 is then locked up under control of relays 16 and 11, the locking circuit includinggrounded battery winding of relay 30, inner armature and front contact of relay 3S outer right-hand armature of relay 16, front contact and outer right-hand armature of relay 11 and ground. Belay 36 in attracting its outer armature opens the looking circuit for relay 16 so that when the operator releases the key and relay 10% releases. relays 13 ant 15 again operate; relay 16 will release which in turn releases relays and 36. The releaseoi relay 16 together with the operation of relay 15 again completes the circuit for relay17 which inductively connects the tone to the operators position and to the chief operators position. If it is desired to remove the tone at this stage of the connection key 107 will again be operated which results in the disconnection of the tone from t e operators position in the manner hereto-fore described.

l i hen the calling subscriber hangs up relay 10 deiinergizes which results in the opening of the circuit of relay 11. The latter in retracting its armatures connects ground to the release conductor thus allow ing the automatic switches to release. Re-

10 in retracting its armatures opens the circuit for relay 101 which thereupon releases. When relay 101 releases ground is connected to the tip side of the trunk and rela 1?; at the automatic exchange is maintaii. operated over the following circuit; ground, armature and back contact of relay 101. tront contact and outer left-hand armature of r lay 113. upper letbhand winding of repeating coil 102, right-hand winding of relay 13 and armature and front contact of relay 12 to grounded battery. Relay 101 in retracting its armature renioves the shunt from relay 120. Relay 120 then operates in series with relay 106 and in attracting its armatures connects battery and ground to the tip and ring conductors of the answering end of the cord circuit which results in the energization of supervisory relay 14-0 and the lighting of the disconnect signal 1411 Relay 140 is energized over a path including ground, upper winding ofretardation coil 142, upper alternatecontacts of relay 120. tips of iack 111 and plug 110 left-hand winding of relay 140. front contact and armature of relay 112, rings of plug 110 and jack 111. lower alternate contactxot' relay 120 and lower winding of retardation coil P12 to grounded. battery. Relay .1 10 in attracting its armature completes a circuit for supervisory lamp 1 11 said circuit including the lower contact of key 121 which is in its operated position, said key having been actuated by' the operator in referring the call to the desk. When the desk operator removes the plug 132 from jack 131 the circuit for relay 130 is opened and lamp 137 is extinguished which indicates to the operator that the desk operator has disconnected. The operator removes the plugs from their associated jacks upon receiving the disconnect signals. whereupon all relays at the toll exchange are released. Relay 113 upon deenergization opens the circuit for relay 13 at the automatic exchange. The,

latter in releasing its armatures restores all relays in the trunk circuits at the automatic exchange to normal and the system is ready for the next call.

That is claimed is:

1. In a telephone system, an office, telephone lines of different classes terminating therein, a second otfice, trunks interconnecting said offices and having two wires only, an. operators position at said second oilice wherein said trunks terminate, a cord circuit thereat, automatic switches at said first otfice adapted to be set under the control of the calling subscriber to seize one of said trunks. and means for immediately automatically indicating the class of the calling line to the operator at the second office as soon as said cord circuit is connected to a seized trunk.

2. In a telephone system, an oilice, telephone lines of different classes terminating therein, a second office, trunks interconnecting said oflices and having two wires only, an operators position at said second oflice wherein said trunks terminate, a cord circuit thereat, an operators telephone set therefor, automatic switches at said first ofi'ice, set under control of a calling line to seize one of said trunks, a tone source associated with certain of said lines automatically connected to said operators telephone set as soon as the cord circuit is connected to said trunk for indicating to the operator the class of the calling line, and means controlled by the operator for removing the tone and for again causing the tone to be impressed upon the trunk at will.

3. In a telephone system, an oiiice, telephone lines of different classes terminating therein, a second oiiice, trunks interconnecting said offices, an operators position at said second ofiice wherein said trunks terminate, automatic switches at said first otlice set under the control of the calling party to seize one of said trunks, a cord circuit at said operators position for seizing said trunk, a tone source automatically connected to said trunk as soon as said trunk is seized by the operator to indicate to the operator the class of the calling line, means controlled by the operator for removing the tone, :1 second operators position, and means con trolled by the operator at the first position for extending the trunk to the second position and for again causing the tone to be impressed on the trunk.

a. In a telephone exchange system, an automatic exchange, a calling line thereat, a source of tone supply associated with said line, a manual exchange, a two-conductor trunk circuit extending between said exchanges terminating in a jack at said manual exchange, a cord circuit at said manual exchange, an operators telephone set connected thereto, means including automatic switches for extending said calling line to said jack, means responsive to-the connection. of said cord circuit with the ack of said trunk circuit for inductively connecting saidsource of tone supply to said operators telephone set, and operator-controlled means for disconnecting sa1d source of tone supply from said operators telephone set.

5 In a telephone exchange system, an automatic exchange, a manual exchange, a-

calling line at said automatic exchange, a tone generator associated with said calling line, an operators position at said manual exchange, means including a two conductor trunk circuit for extending said calling line to said operators position, a relay at said automatic exchange adapted upon energization to inductively connect said tone generator to said operators position, and operator-controlled means for energizing said relay.

6. In a telephone exchange system, an automatic exchange, a manual exchange, a calling line at said automatic exchange, a source of tone supply associated with said calling line, an operators position at said manual exchange, means including a two conductor trunk circuit for automatically extending said calling line to said operators position, a relay at said automatic exchange adapted upon energization to inductively connect said source of tone supply to said operators position, and operator-controlled means for energizing and dec'nergizing said relay.

7 In a telephone exchange system, an au tomatic exchange, a manual exchange, a two conductor trunk circuit extending between said exchanges, a jack at a switchboard in which said trunk circuit terminates at said manual exchange, a calling line at said antomatic exchange, a tone generator associated with said calling line, means including automatic switches for extending said calling line to said jack, a cord circuit at said switchboard, an operators telephone set connected to said cord circuit, a relay associated with the trunk circuit at said automatic exchange adapted upon energization telephone set.

8, In a telephone exchange system, an automatic exchange, a manual exchange, a twoconductor trunk circuit extending between said exchanges, a calling line, automaticswitches operable by the subscriber of said calling line for extending said line to the manual exchange, a tone generator, a relay.

associated with the trunk circuit at the automatic exchange adapted upon energization to inductively connect the tone generator to the talking conductors of said trunk circuit, means responsive to the connection of said cord circuit, with said trunk circuit for energizing said relay, a key associated with said trunk circuit, and means responsive to the actuation of said key for deenergizing said relay.

9. In a telephone exchange system, an automatic exchange, a calling line thereat, a source of tone supply associated with said line, a manual exchange, an operators position at said manual exchange, a two-conductor trunk circuit extending between said exchanges, means including automatic switches for extending said calling line over said trunk circuit to said operators position, a cord circuit at said operators position having an operators telephone set connected thereto, means responsive to the connection of said cord circuit with said trunk circuit for inductively connecting said tone to said telephone set, a second operators position at said manual exchange, means at said firstmentioned operators position for extending said calling line therefrom to said second operators position, and means under the control of the first mentioned operator for disconnecting and connecting said tone.

10in a telephone system, an automatic exchange, a plurality of subscribers lines terminating therein, a tone generator associated with certain of said lines, a manual exchange, means including automatic switches and a two-conductor trunk circuit for extending any of said lines to said manual exchange, a cord circuit at said manual exchange, an operators telephone set connected thereto, means responsive to the connection of said cord circuit with said trunk circuit for inductively connecting said tone generator to said telephone set, operator controlled means for disconnecting said tone generator from said telephone set, a supervisory signal associated with said cord circuit, and means controlled by the subscriber of the calling line for actuating said signal.

In witness whereof, I hereunto subscribe my name this th day of December A. D., 1919.

ARTHUR RAYNSFORD. 

